This crate seamlessly plugs into cv-core and provides pinhole camera models with and without distortion correction.
It can be used to convert image coordinates into real 3d direction vectors (called bearings) pointing towards where
the light came from that hit that pixel. It can also be used to convert backwards from the 3d back to the 2d
using the uncalibrate method from the cv_core::CameraModel trait.

This contains basic camera specifications that one could find on a
manufacturer's website. This only contains parameters that cannot
be changed about a camera. The focal length is not included since
that can typically be changed and images can also be magnified.

A point in normalized image coordinates. This keypoint has been corrected
for distortion and normalized based on the camrea intrinsic matrix.
Please note that the intrinsic matrix accounts for the natural focal length
and any magnification to the image. Ultimately, the key points must be
represented by their position on the camera sensor and normalized to the
focal length of the camera.